1-aryl-5-halopyrazoles

ABSTRACT

1-Aryl-pyrazoles of the general formula ##STR1## in which Hal represents halogen, 
     R 1  and R 3  independently of one another represent cyano, nitro, halogen, alkyl, alkoxy, alkoxycarbonyl, halogenoalkyl, halogenoalkoxy or a radical --S(O) n  --R 6  and 
     R 2 , R 4  and R 5  independently of one another and independently of R 1  and R 3  represent the same radicals as R 1  and R 3 , and additionally represent hydrogen, 
     and wherein 
     R 6  represents alkyl, halogenoalkyl, amino, alkylamino or dialkylamino and n-represents the number 0, 1 or 2 are disclosed. 
     These compounds can be nitrated to form herbicially effective 1-aryl-4-nitropyrazoles.

This is a division of application Ser. No. 816,643, filed Jan. 6, 1986,now U.S. Pat. No. 4,681,618.

The invention relates to 1-aryl-4-nitropyrazoles, several processes fortheir preparation and their use as herbicides.

It is already known that certain 1-aryl-pyrazoles, such as, for example,4-cyano-5-propionamido-1-(2,3,4-trichlorophenyl)-pyrazole, haveherbicidal properties (see, for example, DE-OS (German PublishedSpecification) No. 3,226,513).

However, the herbicidal activity of these already known compoundstowards weeds, like their tolerances towards important crop plants, isnot always completely satisfactory in all fields of use.

New 1-aryl-4-nitropyrazoles of the general formula (I) ##STR2## in whichHal represents halogen,

R¹ and R³ independently of one another represent cyano, nitro, halogen,alkyl, alkoxy, alkoxycarbonyl, halogenoalkyl, halogenoalkoxy or aradical --S(O)_(n) --R⁶ and

R², R⁴ and R⁵ independently of one another and independently of R¹ andR³ represent the same radicals as R¹ and R³, and additionally representhydrogen,

and wherein

R⁶ represents alkyl, halogenoalkyl, amino, alkylamino or dialkylaminoand

n represents the number 0, 1 or 2,

have now been found.

It has furthermore been found that the new 1-aryl-4-nitropyrazoles ofthe general formula (I) ##STR3## in which Hal represents halogen,

R¹ and R³ independently of one another represent cyano, nitro, halogen,alkyl, alkoxy, alkoxycarbonyl, halogenoalkyl, halogenoalkoxy or aradical --S(O)_(n) --R⁶ and

R², R⁴ and R⁵ independently of one another and independently of R¹ andR³ represent the same radicals as R¹ and R³, and additionally representhydrogen,

and wherein

R⁶ represents alkyl, halogenoalkyl, amino, alkylamino or dialkylaminoand

n represents the number 0, 1 or 2,

are obtained by a process in which

(a) 1-arylpyrazoles of the general formula (II) ##STR4## in which R¹,R², R³, R⁴, R⁵ and Hal have the above-mentioned meaning,

are reacted with nitric acid, if appropriate in the presence of adiluent and if appropriate in the presence of a catalyst, or in which

(b) 5-amino-4-nitropyrazoles of the formula (III) ##STR5## in which R¹,R², R³, R⁴, R⁵ and Hal have the above-mentioned meaning,

are reacted with nitrite compounds of the formula (IV)

    R--O--N═O                                              (IV)

in which

R represents hydrogen, an alkali metal cation or alkyl,

and a haloform of the formula (V) ##STR6## in which Hal has theabovementioned meaning,

if appropriate in the presence of a catalyst, or in which

(c) the 1-aryl-4-nitropyrazoles obtainable according to process (a) or(b), of the formula (I) ##STR7## in which R¹, R², R³, R⁴, R⁵ and Halhave the above-mentioned meaning,

are reacted with halides of the formula (VI)

    M.sup.⊕ Hal'.sup.⊖                             (VI)

in which

M.sup.⊕ represents one equivalent of a metal cation or an optionallysubstituted ammonium ion and

Hal'.sup.⊕ represents halogen, but is other than Hal,

if appropriate in the presence of a diluent and if appropriate in thepresence of a phase transfer catalyst.

In this manner, from a particular halogen derivative of the1-aryl-4-nitropyrazoles of the formula (I), for example the chlorinederivative, transhalogenation, for example with sodium iodide, gives thecorresponding halogen derivatives of the 1-aryl-4-nitropyrazoles of theformula (I) in which, for example, chlorine is replaced by iodine.

Finally, it has been found that the new 1-aryl-4-nitropyrazoles of thegeneral formula (I) have herbicidal properties, and in particular alsoselective herbicidal properties.

Surprisingly, the 1-aryl-4-nitropyrazoles of the general formula (I)according to the invention, whilst having a comparable generallyherbicidal activity against weeds which are difficult to combat, exhibita considerably improved selectivity towards crop plants in comparisonwith the 1-arylpyrazoles known from the prior art, such as, for example,4-cyano-5-propionylamino-1-(2,3,4-trichloro-phenyl)pyrazole, which areclosely related compounds chemically and from the point of view of theiraction.

Formula (I) provides a general definition of the 1-aryl-4-nitropyrazolesaccording to the invention. Preferred compounds of the formula (I) arethose in which

Hal represents halogen,

R¹ and R³ independently of one another represent cyano, nitro orhalogen, or represent in each case straight-chain or branched alkyl,alkoxy or alkoxycarbonyl with in each case 1 to 4 carbon atoms in thealkyl part, or represent in each case straight-chain or branchedhalogenoalkyl or halogenoalkoxy with in each case 1 to 4 carbon atomsand 1 to 9 identical or different halogen atoms, or represent a radical--S(O)_(n) --R⁶ and

R², R⁴ and R⁵ independently of one another and independently of R¹ andR³ represent the same radicals as R¹ and R³ and also represent hydrogen,

and wherein

R⁶ represents amino, or in each case straight-chain or branched alkyl,alkylamino, dialkylamino or halogenoalkyl with in each case 1 to 4carbon atoms in the individual alkyl parts and, in the case ofhalogenoalkyl, with 1 to 9 identical or different halogen atoms and

n represents the number 0, 1 or 2.

Particularly preferred compounds of the formula (I) are those in which

Hal represents fluorine, chlorine, bromine or iodine, R¹ and R³independently of one another represent cyano, nitro, fluorine, chlorine,bromine, iodine, methyl, ethyl n- or i-propyl or n-, i-, s- or t-butyl,or represent methoxy, ethoxy, methoxycarbonyl or ethoxycarbonyl, orrepresent trifluoromethyl, trichloromethyl, dichlorofluoromethyl,difluorochloromethyl, chloromethyl, dichloromethyl, difluoromethyl,pentafluoroethyl, tetrafluoroethyl, trifluorochloroethyl,trifluoroethyl, difluorodichloroethyl, trifluorodichloroethyl orpentachloroethyl, or represent trifluoromethoxy, trichloromethoxy,dichlorofluoromethoxy, difluorochloromethoxy, chloromethoxy,dichloromethoxy, difluoromethoxy, pentafluoroethoxy, tetrafluoroethoxy,trifluorochloroethoxy, trifluoroethoxy, difluorodichloroethoxy,trifluorodichloroethoxy or pentachloroethoxy, or represent a radical--S(O)_(n) --R⁶ and

R², R⁴ and R⁵ independently of one another and independently of R¹ andR³ represent the same radicals as R¹ and R³, and also representhydrogen,

and wherein

R⁶ represents amino, methylamino, ethylamino, dimethylamino,diethylamino, fluorodichloromethyl, difluoromethyl, tetrafluoroethyl,trichloroethyl, trifluoromethyl, methyl or ethyl and

n represents the number 0, 1 or 2.

The 1-aryl-4-nitropyrazoles of the general formula (I) listed by way oftheir formulae in the following table may be mentioned specifically, inaddition to the compounds mentioned in the preparation examples:##STR8##

                  TABLE 1                                                         ______________________________________                                        Hal     R.sup.1  R.sup.2                                                                              R.sup.3    R.sup.4                                                                            R.sup.5                               ______________________________________                                        Cl      Cl       H      Cl         H    H                                     Cl      Cl       Cl     Cl         H    H                                     Cl      Cl       H      Cl         H    Cl                                    Cl      NO.sub.2 H      NO.sub.2   H    H                                     Cl      Cl       H      CF.sub.3   H    H                                     Cl      Cl       H      CF.sub.3   H    Cl                                    Cl      CF.sub.3 H      CF.sub.3   H    H                                     Cl      Cl       Cl     CF.sub.3   H    Cl                                    Cl      Cl       Cl     Cl         H    Cl                                    Cl      Cl       H      OCF.sub.3  H    H                                     Cl      Cl       H      OCF.sub.3  H    Cl                                    Cl      Cl       H      SCF.sub.3  H    H                                     Cl      Cl       H      SCF.sub.3  H    Cl                                    Cl      Cl       Cl     SCF.sub.3  H    H                                     Cl      Cl       Cl     SCF.sub.3  H    Cl                                    Cl      F        F      OCF.sub.3  H    F                                     Cl      F        F      OCF.sub.3  F    F                                     Cl      Cl       Cl     OCF.sub.3  H    H                                     Cl      Br       H      SCF.sub.3  H    H                                     Cl      Br       H      OCF.sub.3  H    Br                                    Cl      NO.sub.2 H      NO.sub.2   H    NO.sub.2                              Cl      F        H      OCF.sub.3  H    F                                     Cl      F        H      CF.sub.3   H    F                                     Cl      F        F      SCF.sub.3  H    F                                     Cl      F        H      SCF.sub.3  H    F                                     Cl      I        H      OCF.sub.3  H    H                                     Cl      Cl       H      SO.sub.2 CF.sub.3                                                                        H    Cl                                    Cl      CF.sub.3 H      CF.sub.3   H    CF.sub.3                              Cl      CF.sub.3 H      SO.sub.2 CF.sub.3                                                                        H    CF.sub.3                              Cl      CF.sub.3 H      SCF.sub.3  H    CF.sub.3                              Cl      CF.sub.3 H      SCF.sub.3  H    H                                     Cl      Br       H      CF.sub.3   H    Br                                    Cl      F        F      SO.sub.2 CF.sub.3                                                                        H    F                                     Cl      Cl       Cl     SCF.sub.3  Cl   Cl                                    Cl      Cl       F      Cl         H    Cl                                    Cl      F        F      F          F    F                                     Cl      F        F      CF.sub.3   F    F                                     Cl      Cl       Cl     Cl         Cl   Cl                                    Cl      Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    Cl      Cl       Cl     SO.sub.2 CF.sub.3                                                                        H    H                                     Cl      Br       H      SO.sub.2 CF.sub.3                                                                        H    Br                                    Cl      NO.sub.2 H      CF.sub.3   H    H                                     Cl      F        H      SO.sub.2 CF.sub.3                                                                        H    F                                     Cl      Cl       H      OCH.sub.3  H    Cl                                    Cl      Cl       H      SCH.sub.3  H    Cl                                    Cl      F        H      F          H    F                                     Cl      Cl       H      SO.sub.2 CH.sub.3                                                                        H    H                                     Cl      Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    Cl      Cl       H      SO.sub.2 CClF.sub.2                                                                      H    Cl                                    Cl      Br       H      OCF.sub.3  H    H                                     Cl      Br       H      SCF.sub.3  H    Br                                    Cl      Br       H      Br         H    Br                                    Cl      Br       H      Br         H    H                                     Cl      Br       H      Cl         H    Cl                                    Cl      Cl       H      Br         H    Cl                                    Cl      Cl       H      Br         H    Br                                    Cl      Cl       H      SO.sub.2 CF.sub.3                                                                        H    H                                     Cl      Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Cl      Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Cl                                    Cl      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Cl      Cl       H      OCF.sub.2 Cl                                                                             H    H                                     Cl      Cl       H      OCF.sub.2 Cl                                                                             H    Cl                                    Cl      Cl       H      OCF.sub.2 CHF.sub.2                                                                      H    Cl                                    Cl      Cl       H      CF.sub.2 Cl                                                                              H    Cl                                    Cl      Cl       H      OCF.sub.2 Cl                                                                             H    H                                     Cl      Cl       H      OCHF.sub.2 H    H                                     Cl      Cl       H      OCHF.sub.2 H    Cl                                    Cl      Cl       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     Cl      Cl       H      OCH.sub.2 CF.sub.3                                                                       H    Cl                                    Cl      Cl       H      OCF.sub.2 CHFCl                                                                          H    H                                     Cl      Cl       H      OCF.sub.2 CHFCl                                                                          H    Cl                                    Cl      Cl       H      CHF.sub.2  H    Cl                                    Cl      Cl       H      CHF.sub.2  H    H                                     Cl      Br       H      OCH.sub.2 CF.sub.3                                                                       H    Br                                    Cl      Br       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     Cl      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Cl      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Br                                    Cl      Br       H      SO.sub.2 CH.sub.3                                                                        H    H                                     Cl      Br       H      SO.sub.2 CH.sub.3                                                                        H    Br                                    Br      Cl       H      Cl         H    H                                     Br      Cl       Cl     Cl         H    H                                     Br      Cl       H      Cl         H    Cl                                    Br      NO.sub.2 H      NO.sub.2   H    H                                     Br      Cl       H      CF.sub.3   H    H                                     Br      Cl       H      CF.sub.3   H    Cl                                    Br      CF.sub.3 H      CF.sub.3   H    H                                     Br      Cl       Cl     CF.sub.3   H    Cl                                    Br      Cl       Cl     Cl         H    Cl                                    Br      Cl       H      OCF.sub.3  H    H                                     Br      Cl       H      OCF.sub.3  H    Cl                                    Br      Cl       H      SCF.sub.3  H    H                                     Br      Cl       H      SCF.sub.3  H    Cl                                    Br      Cl       Cl     SCF.sub.3  H    H                                     Br      Cl       Cl     SCF.sub.3  H    Cl                                    Br      F        F      OCF.sub.3  H    F                                     Br      F        F      OCF.sub.3  F    F                                     Br      Cl       Cl     OCF.sub.3  H    H                                     Br      Br       H      SCF.sub.3  H    H                                     Br      Br       H      OCF.sub.3  H    Br                                    Br      NO.sub.2 H      NO.sub.2   H    NO.sub.2                              Br      F        H      OCF.sub.3  H    F                                     Br      F        H      CF.sub.3   H    F                                     Br      F        F      SCF.sub.3  H    F                                     Br      F        H      SCF.sub.3  H    F                                     Br      I        H      OCF.sub.3  H    H                                     Br      Cl       H      SO.sub.2 CF.sub.3                                                                        H    Cl                                    Br      CF.sub.3 H      CF.sub.3   H    CF.sub.3                              Br      CF.sub.3 H      SO.sub.2 CF.sub.3                                                                        H    CF.sub.3                              Br      CF.sub.3 H      SCF.sub.3  H    CF.sub.3                              Br      CF.sub.3 H      SCF.sub.3  H    H                                     Br      Br       H      CF.sub.3   H    Br                                    Br      F        F      SO.sub.2 CF.sub.3                                                                        H    F                                     Br      Cl       Cl     SCF.sub.3  Cl   Cl                                    Br      Cl       F      Cl         H    Cl                                    Br      F        F      F          F    F                                     Br      F        F      CF.sub.3   F    F                                     Br      Cl       Cl     Cl         Cl   Cl                                    Br      Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    Br      Cl       Cl     SO.sub.2 CF.sub.3                                                                        H    H                                     Br      Br       H      SO.sub.2 CF.sub.3                                                                        H    Br                                    Br      NO.sub.2 H      CF.sub.3   H    H                                     Br      F        H      SO.sub.2 CF.sub.3                                                                        H    F                                     Br      Cl       H      OCH.sub.3  H    Cl                                    Br      Cl       H      SCH.sub.3  H    Cl                                    Br      F        H      F          H    F                                     Br      Cl       H      SO.sub.2 CH.sub.3                                                                        H    H                                     Br      Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    Br      Cl       H      SO.sub.2 CClF.sub.2                                                                      H    Cl                                    Br      Br       H      OCF.sub.3  H    H                                     Br      Br       H      SCF.sub.3  H    Br                                    Br      Br       H      Br         H    Br                                    Br      Br       H      Br         H    H                                     Br      Br       H      Cl         H    Cl                                    Br      Cl       H      Br         H    Cl                                    Br      Cl       H      Br         H    Br                                    Br      Cl       H      SO.sub.2 CF.sub.3                                                                        H    H                                     Br      Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Br      Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Cl                                    Br      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Br      Cl       H      OCF.sub.2 Cl                                                                             H    H                                     Br      Cl       H      OCF.sub.2 Cl                                                                             H    Cl                                    Br      Cl       H      OCF.sub.2 CHF.sub.2                                                                      H    Cl                                    Br      Cl       H      CF.sub.2 Cl                                                                              H    Cl                                    Br      Cl       H      OCF.sub.2 Cl                                                                             H    H                                     Br      Cl       H      OCHF.sub.2 H    H                                     Br      Cl       H      OCHF.sub.2 H    Cl                                    Br      Cl       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     Br      Cl       H      OCH.sub.2 CF.sub.3                                                                       H    Cl                                    Br      Cl       H      OCF.sub.2 CHFCl                                                                          H    H                                     Br      Cl       H      OCF.sub.2 CHFCl                                                                          H    Cl                                    Br      Cl       H      CHF.sub.2  H    Cl                                    Br      Cl       H      CHF.sub.2  H    H                                     Br      Br       H      OCH.sub.2 CF.sub.3                                                                       H    Br                                    Br      Br       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     Br      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     Br      Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Br                                    Br      Br       H      SO.sub.2 CH.sub.3                                                                        H    H                                     Br      Br       H      SO.sub.2 CH.sub.3                                                                        H    Br                                    F       Cl       H      Cl         H    H                                     F       Cl       Cl     Cl         H    H                                     F       Cl       H      Cl         H    Cl                                    F       NO.sub.2 H      NO.sub.2   H    H                                     F       Cl       H      CF.sub.3   H    H                                     F       Cl       H      CF.sub.3   H    Cl                                    F       CF.sub.3 H      CF.sub.3   H    H                                     F       Cl       Cl     CF.sub.3   H    Cl                                    F       Cl       Cl     Cl         H    Cl                                    F       Cl       H      OCF.sub.3  H    H                                     F       Cl       H      OCF.sub.3  H    Cl                                    F       Cl       H      SCF.sub.3  H    H                                     F       Cl       H      SCF.sub.3  H    Cl                                    F       Cl       Cl     SCF.sub.3  H    H                                     F       Cl       Cl     SCF.sub.3  H    Cl                                    F       F        F      OCF.sub.3  H    F                                     F       F        F      OCF.sub.3  F    F                                     F       Cl       Cl     OCF.sub.3  H    H                                     F       Br       H      SCF.sub.3  H    H                                     F       Br       H      OCF.sub.3  H    Br                                    F       NO.sub.2 H      NO.sub.2   H    NO.sub.2                              F       F        H      OCF.sub.3  H    F                                     F       F        H      CF.sub.3   H    F                                     F       F        F      SCF.sub.3  H    F                                     F       F        H      SCF.sub.3  H    F                                     F       I        H      OCF.sub.3  H    H                                     F       Cl       H      SO.sub.2 CF.sub.3                                                                        H    Cl                                    F       CF.sub.3 H      CF.sub.3   H    CF.sub.3                              F       CF.sub.3 H      SO.sub.2 CF.sub.3                                                                        H    CF.sub.3                              F       CF.sub.3 H      SCF.sub.3  H    CF.sub.3                              F       CF.sub.3 H      SCF.sub.3  H    H                                     F       Br       H      CF.sub.3   H    Br                                    F       F        F      SO.sub.2 CF.sub.3                                                                        H    F                                     F       Cl       Cl     SCF.sub.3  Cl   Cl                                    F       Cl       F      Cl         H    Cl                                    F       F        F      F          F    F                                     F       F        F      CF.sub.3   F    F                                     F       Cl       Cl     Cl         Cl   Cl                                    F       Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    F       Cl       Cl     SO.sub.2 CF.sub.3                                                                        H    H                                     F       Br       H      SO.sub.2 CF.sub.3                                                                        H    Br                                    F       NO.sub.2 H      CF.sub.3   H    H                                     F       F        H      SO.sub.2 CF.sub.3                                                                        H    F                                     F       Cl       H      OCH.sub.3  H    Cl                                    F       Cl       H      SCH.sub.3  H    Cl                                    F       F        H      F          H    F                                     F       Cl       H      SO.sub.2 CH.sub.3                                                                        H    H                                     F       Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    F       Cl       H      SO.sub.2 CClF.sub.2                                                                      H    Cl                                    F       Br       H      OCF.sub.3  H    H                                     F       Br       H      SCF.sub.3  H    Br                                    F       Br       H      Br         H    Br                                    F       Br       H      Br         H    H                                     F       Br       H      Cl         H    Cl                                    F       Cl       H      Br         H    Cl                                    F       Cl       H      Br         H    Br                                    F       Cl       H      SO.sub.2 CF.sub.3                                                                        H    H                                     F       Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     F       Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Cl                                    F       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     F       Cl       H      OCF.sub.2 Cl                                                                             H    H                                     F       Cl       H      OCF.sub.2 Cl                                                                             H    Cl                                    F       Cl       H      OCF.sub.2 CHF.sub.2                                                                      H    Cl                                    F       Cl       H      CF.sub.2 Cl                                                                              H    Cl                                    F       Cl       H      OCF.sub.2 Cl                                                                             H    H                                     F       Cl       H      OCHF.sub.2 H    H                                     F       Cl       H      OCHF.sub.2 H    Cl                                    F       Cl       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     F       Cl       H      OCH.sub.2 CF.sub.3                                                                       H    Cl                                    F       Cl       H      OCF.sub.2 CHFCl                                                                          H    H                                     F       Cl       H      OCF.sub.2 CHFCl                                                                          H    Cl                                    F       Cl       H      CHF.sub.2  H    Cl                                    F       Cl       H      CHF.sub.2  H    H                                     F       Br       H      OCH.sub.2 CF.sub.3                                                                       H    Br                                    F       Br       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     F       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     F       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Br                                    F       Br       H      SO.sub.2 CH.sub.3                                                                        H    H                                     F       Br       H      SO.sub.2 CH.sub.3                                                                        H    Br                                    I       Cl       H      Cl         H    H                                     I       Cl       Cl     Cl         H    H                                     I       Cl       H      Cl         H    Cl                                    I       NO.sub.2 H      NO.sub.2   H    H                                     I       Cl       H      CF.sub.3   H    H                                     I       Cl       H      CF.sub.3   H    Cl                                    I       CF.sub.3 H      CF.sub.3   H    H                                     I       Cl       Cl     CF.sub.3   H    Cl                                    I       Cl       Cl     Cl         H    Cl                                    I       Cl       H      OCF.sub.3  H    H                                     I       Cl       H      OCF.sub.3  H    Cl                                    I       Cl       H      SCF.sub.3  H    H                                     I       Cl       H      SCF.sub.3  H    Cl                                    I       Cl       Cl     SCF.sub.3  H    H                                     I       Cl       Cl     SCF.sub.3  H    Cl                                    I       F        F      OCF.sub.3  H    F                                     I       F        F      OCF.sub.3  F    F                                     I       Cl       Cl     OCF.sub.3  H    H                                     I       Br       H      SCF.sub.3  H    H                                     I       Br       H      OCF.sub.3  H    Br                                    I       NO.sub.2 H      NO.sub.2   H    NO.sub.2                              I       F        H      OCF.sub. 3 H    F                                     I       F        H      CF.sub.3   H    F                                     I       F        F      SCF.sub.3  H    F                                     I       F        H      SCF.sub.3  H    F                                     I       I        H      OCF.sub.3  H    H                                     I       Cl       H      SO.sub.2 CF.sub.3                                                                        H    Cl                                    I       CF.sub.3 H      CF.sub.3   H    CF.sub.3                              I       CF.sub.3 H      SO.sub.2 CF.sub.3                                                                        H    CF.sub.3                              I       CF.sub.3 H      SCF.sub.3  H    CF.sub.3                              I       CF.sub.3 H      SCF.sub.3  H    H                                     I       Br       H      CF.sub.3   H    Br                                    I       F        F      SO.sub.2 CF.sub.3                                                                        H    F                                     I       Cl       Cl     SCF.sub.3  Cl   Cl                                    I       Cl       F      Cl         H    Cl                                    I       F        F      F          F    F                                     I       F        F      CF.sub.3   F    F                                     I       Cl       Cl     Cl         Cl   Cl                                    I       Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    I       Cl       Cl     SO.sub.2 CF.sub.3                                                                        H    H                                     I       Br       H      SO.sub.2 CF.sub.3                                                                        H    Br                                    I       NO.sub.2 H      CF.sub.3   H    H                                     I       F        H      SO.sub.2 CF.sub.3                                                                        H    F                                     I       Cl       H      OCH.sub.3  H    Cl                                    I       Cl       H      SCH.sub.3  H    Cl                                    I       F        H      F          H    F                                     I       Cl       H      SO.sub.2 CH.sub.3                                                                        H    H                                     I       Cl       H      SO.sub.2 CH.sub.3                                                                        H    Cl                                    I       Cl       H      SO.sub.2 CClF.sub.2                                                                      H    Cl                                    I       Br       H      OCF.sub.3  H    H                                     I       Br       H      SCF.sub.3  H    Br                                    I       Br       H      Br         H    Br                                    I       Br       H      Br         H    H                                     I       Br       H      Cl         H    Cl                                    I       Cl       H      Br         H    Cl                                    I       Cl       H      Br         H    Br                                    I       Cl       H      SO.sub.2 CF.sub.3                                                                        H    H                                     I       Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     I       Cl       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Cl                                    I       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     I       Cl       H      OCF.sub.2 Cl                                                                             H    H                                     I       Cl       H      OCF.sub.2 Cl                                                                             H    Cl                                    I       Cl       H      OCF.sub.2 CHF.sub.2                                                                      H    Cl                                    I       Cl       H      CF.sub.2 Cl                                                                              H    Cl                                    I       Cl       H      OCF.sub.2 Cl                                                                             H    H                                     I       Cl       H      OCHF.sub.2 H    H                                     I       Cl       H      OCHF.sub.2 H    Cl                                    I       Cl       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     I       Cl       H      OCH.sub.2 CF.sub.3                                                                       H    Cl                                    I       Cl       H      OCF.sub.2 CHFCl                                                                          H    H                                     I       Cl       H      OCF.sub.2 CHFCl                                                                          H    Cl                                    I       Cl       H      CHF.sub.2  H    Cl                                    I       Cl       H      CHF.sub.2  H    H                                     I       Br       H      OCH.sub.2 CF.sub.3                                                                       H    Br                                    I       Br       H      OCH.sub.2 CF.sub.3                                                                       H    H                                     I       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    H                                     I       Br       H      SO.sub.2 CF.sub.2 Cl                                                                     H    Br                                    I       Br       H      SO.sub.2 CH.sub.3                                                                        H    H                                     I       Br       H      SO.sub.2 CH.sub.3                                                                        H    Br                                    ______________________________________                                    

If, for example, 5-chloro-1-(2,4,6-trichlorophenyl)pyrazole and nitricacid are used as starting substances, the course of the reaction inprocess (a) according to the invention can be represented by thefollowing equation: ##STR9##

If, for example, 5-amino-4-nitro-1-(2,4,6-trichlorophenyl)-pyrazole,t-butyl nitrite and bromoform are used as starting substances, thecourse of the reaction in process (b) according to the invention can berepresented by the following equation: ##STR10##

If, for example, 5-chloro-4-nitro-1-(2,3,4-trichlorophenyl)-pyrazole andsodium iodide are used as starting substances, the course of thereaction in process (c) according to the invention can be represented bythe following equation: ##STR11##

Formula (II) provides a general definition of the 1-arylpyrazolesrequired as starting substances for carrying out process (a) accordingto the invention. In this formula (II), R¹, R², R³, R⁴, R⁵ and Halpreferably represent those radicals which have already been mentioned aspreferred for these substituents in connection with the description ofthe substances of the formula (I) according to the invention.

The 1-arylpyrazoles of the formula (II) are not yet known. They areobtained by a process in which alkoxymethylenemalonates of the formula(VII) ##STR12## in which R⁷ and R⁸ independently of one another in eachcase represent alkyl, in particular methyl or ethyl,

are initially reacted with phenylhydrazines of the formula (VIII)##STR13## in which R¹, R², R³, R⁴ and R⁵ have the abovementionedmeaning,

in a first stage, if appropriate in the presence of a diluent, such as,for example, methanol or ethanol, at temperatures between +10° C. and+80° C.

If appropriate, the intermediate product which intermediately occurshere, of the formula (VIIIa) ##STR14## in which R¹, R², R³, R⁴, R⁵ andR⁸ have the above-mentioned meaning,

can also be isolated and cyclised in a separate reaction stage.

The pyrazolecarboxylic acid esters thus obtainable, of the formula (IX)##STR15## in which R¹, R², R³, R⁴, R⁵ and R⁸ have the above-mentionedmeaning,

are decarboxylated in a 2nd stage, if appropriate in the presence of adiluent, such as, for example, methanol, and if appropriate in thepresence of a base, such as, for example, sodium hydroxide, attemperatures between 30° C. and 70° C. and the pyrazolinones thusobtainable, of the formula (X) ##STR16## in which R¹, R², R³, R⁴ and R⁵have the abovementioned meaning,

are then reacted with halogenating agents, such as, for example,phosphorus oxychloride or phosphorus oxybromide, in a 3rd stage bycustomary known processes (see, for example, Ber. dtsch. chem. Ges. 28,35 [1895] or Liebigs Ann. Chem. 373, 129 [1910]).

If appropriate, the cyclisation and subsequent decarboxylation can alsobe carried out in one reaction stage as a "one-pot process" (see, forexample, Leibigs Ann. Chem. 373, 142 (1910) and the preparationexamples).

The alkoxymethylenemalonates of the formula (VII) are generally knowncompounds of organic chemistry.

The phenylhydrazines of the formula (VIII) are known in most cases, orthey can be prepared by known processes in a simple analogous manner(see, for example, Houben-Weyl "Methoden der organischen Chemie"("Methods of Organic Chemistry") Volume X, 2, page 203, Thieme VerlagStuttgart 1967), for example by a process in which the known anilines ofthe formula (XI) ##STR17## in which R¹, R², R³, R⁴ and R⁵ have theabovementioned meaning,

are reacted with sodium nitrite in the presence of an acid, such as, forexample, sulfuric acid, and then with tin(II) chloride, likewise in thepresence of an acid, such as, for example, hydrochloric acid, attemperatures between -20° C. and +80° C., or, alternatively, the knownchlorobenzenes, of the formula (XIa) ##STR18## in which R¹, R², R³, R⁴and R⁵ have the abovementioned meaning,

are reacted with hydrazine hydrate, if appropriate in the presence of adiluent, such as, for example, dioxane, at temperatures between 20° C.and 150° C.

Formula (III) provides a general definition of the5-amino-4-nitropyrazoles required as starting substances for carryingout process (b) according to the invention. In this formula, R¹, R², R³,R⁴ and R⁵ preferably represent those substituents which have alreadybeen mentioned as preferred for these radicals in connection with thedescription of the substances of the formula (I) according to theinvention.

The 5-amino-4-nitropyrazoles of the formula (III) are likewise not yetknown. However, they are the subject of a previous not published PatentApplication which has been filed by the Applicant Company (German Pat.No. 3,402,308 of 24.01.1984).

They are obtained, for example, by a process in which phenylhydrazinesof the formula (VIII) ##STR19## in which R¹, R², R³, R⁴ and R⁵ have theabovementioned meaning,

are reacted either with acrylonitrile derivatives of the formula (XII)##STR20## in which A represents halogen, hydroxyl, or alkoxy, inparticular chlorine, bromine, hydroxyl methoxy or ethoxy,

or with 2-halogenoacrylonitriles of the formula (XIIa) ##STR21## inwhich Hal" represents halogen, in particular chlorine or bromine,

or with 2,3-dihalogenopropionitriles of the formula (XIIb) ##STR22## inwhich Hal" represents halogen, in particular chlorine or bromine,

initially in one stage, if appropriate in the presence of a diluent,such as, for example, methanol, and if appropriate in the presence of areaction auxiliary, such as, for example, acetic acid, at temperaturesbetween -20° C. and +20° C., to give the phenylhydrazines of the formula(XIII) ##STR23## in which R¹, R², R³, R⁴ and R⁵ have the abovementionedmeaning and

Z represents one of the radicals ##STR24## wherein Hal" and Hal"' havethe above mentioned meaning and represent identical or different halogenatoms,

and these are cyclised in a 2nd stage, if appropriate in the presence ofa diluent, such as, for example, methanol, and if appropriate in thepresence of an acid-binding agent, such as, for example, sodiumcarbonate, at temperatures between +50° C. and +150° C., or are cycliseddirectly in one reaction step, without isolation of the intermediatestage of the formula (XIII), if appropriate in the presence of adiluent, such as, for example, methanol, at temperatures between +50° C.and +150° C., to give the 5-amino-pyrazoles of the formula (XIV)##STR25## in which R¹, R², R³, R⁴ and R⁵ have the abovementionedmeaning,

and these are nitrated in a 3rd stage with nitric acid, if appropriatein the presence of a diluent, such as, for example, acetic acid, and ifappropriate in the presence of a catalyst, such as, for example, aceticanhydride, at temperatures between -20° C. and +150° C.

The acrylonitrile derivatives of the formula (XII) are known (see, forexample, DE-OS (German Published Specification) No. 3,129,429, EuropeanPat. No. 34,945; J. Chem. Soc. D. 1970, 1255; Can. J. Chem. 48,2104-2109 (1970), J. Heterocyclic Chem. 19, 1267-1273 (1982); and Can.J. Chem. 51, 1239-1244 (1973)), or they can be obtained by processeswhich are known from the literature, in a simple analogous manner.

The 2-halogenoacrylonitriles of the formula (XIIa) and the2,3-dihalogeno-propionitriles of the formula (XIIb) are likewise known(see, for example, J. Prakt. Chem. 321, 93 [1979]), J. HeterocyclicChem. 19, 1265 [1982]; and J. Heterocyclic Chem. 19, 1267 [1982]).

Formula (IV) provides a general definition of the nitrite compoundsfurthermore required as starting substances for carrying out process (b)according to the invention. In this formula, R preferably representshydrogen, or represents a sodium or potassium cation, or representsstraight-chain or branched alkyl with 1 to 4 carbon atoms.

The nitrite compounds of the formula (IV) are generally known basicchemicals.

Formula (V) provides a general definition of the haloforms furthermorerequired as starting substances for carrying out process (b) accordingto the invention. In this formula (V), Hal preferably representschlorine, bromine or iodine.

The haloforms of the formula (V) are likewise generally known compoundsof organic chemistry.

The compounds according to the invention of the 1-aryl-4-nitropyrazolesof the formula (I) which are obtainable with the aid of processes (a)and (b) according to the invention are employed as starting substancesin carrying out process (c) according to the invention.

Formula (VI) provides a general definition of the halides furthermorerequired as starting substances for carrying out process (c) accordingto the invention. In this formula (VI), M.sup.⊕ preferably represents asodium or potassium cation, or represents an ammonium ortetraalkylammonium ion, possible alkyl radicals being those with 1 to 12carbon atoms. Hal' represents fluorine, chlorine, bromine or iodine.

The halides of the formula (VI) are likewise generally known compoundsof organic chemistry.

Possible diluents for carrying out process (a) according to theinvention are all the solvents which can usually be employed for suchnitration reactions. The acids possible as reagents or mixtures thereofwith catalyst acid, such as, for example, sulfuric acid, nitric acid,acetic anhydride or nitrating acid, are preferably simultaneously usedas the diluent. If appropriate, inert organic solvents, such as, forexample, glacial acetic acid or chlorinated hydrocarbons, such asmethylene chloride, chloroform or carbon tetrachloride, are alsopossible diluents.

Possible catalysts or reaction auxiliaries for carrying out process (a)according to the invention are likewise the catalysts usual for suchnitrations; acid catalysts, such as, for example, sulfuric acid oracetic anhydride, are preferably used.

The reaction temperatures can be varied within a substantial range incarrying out process (a) according to the invention. In general, thereaction is carried out between -50° C. and +200° C., preferably between-20° C. and +150° C.

For carrying out process (a) according to the invention, in general 1.0to 100 moles, preferably 1.0 to 50 moles, of nitric acid and, ifappropriate, 0.1 to 10 moles of catalyst are employed per mole of1-arylpyrazole of the formula (II).

The reaction is carried out and the reaction products of the formula (I)are worked up and isolated in the generally customary manner.

Possible diluents for carrying out process (b) according to theinvention are all the solvents which can usually be employed for suchdiazotisation reactions, such as, for example, acetic acid or dioxane. Acorresponding excess of the haloform simultaneously employed as areactant is preferably used as the diluent. A corresponding excess of acatalyst acid which can be used, if appropriate, can also simultaneouslybe employed as the diluent.

Possible catalysts for carrying out process (b) according to theinvention are all the catalysts customary for such diazotisationreactions. Acids, such as, for example, hydrochloric acid, hydrobromicacid or sulfuric acid, are preferably used.

The reaction temperatures can be varied within certain ranges forcarrying out process (b) according to the invention. In general, thereaction is carried out between -20° C. and +120° C., preferably between0° C. and +80° C.

For carrying out process (b) according to the invention, in general 1.0to 100 moles of haloform of the formula (V) and 1.0 to 10 moles ofnitrite of the formula (IV) are employed per mole of5-amino-4-nitropyrazole of the formula (III). The reaction is carriedout and the reaction products are worked up and isolated analogously toknown processes (see, for example, "Organikum" 15th edition, VEBDeutscher Verlag der Wissenschaften Berlin 1981, page 652 et seq. or J.Chem. Soc. C 1966, 1249 or Rev. Latinoam. Quim. 13, 100-102 (1982)).

Possible diluents for carrying out process (c) according to theinvention are inert organic solvents.

These include, in particular, aliphatic or aromatic, optionallyhalogenated hydrocarbons, such as, for example, benzine, benzene,toluene, xylene, chlorobenzene, petroleum ether, hexane, cyclohexane,methylene chloride, chloroform or carbon tetrachloride, ethers, such asdiethyl ether, dioxane, tetrahydrofuran or ethylene glycol dimethyl ordiethyl ether, ketones, such as acetone or butanone, nitriles, such asacetonitrile or propionitrile, amides, such as dimethylformamide,dimethylacetamide, N-methylformanilide, N-methylpyrrolidone orhexamethylphosphoric acid triamide, esters, such as ethyl acetate,sulfoxides or sulfones, such as dimethylsulfoxide or sulfolane, oralcohols, such as methanol, ethanol or propanol.

Possible catalysts for carrying out process (c) according to theinvention are quaternary ammonium or phosphonium salts or cyclicpolyethers.

Examples which may be mentioned of such catalysts are:tetrabutylammonium iodide, tetrabutylammonium bromide,tributylmethylphosphonium bromide, trimethyl-C₁₃ /C₁₅ -alkylammoniumchloride, dibenzyl-dimethyl-ammonium-methyl sulfate, dimethyl-C₁₂ /C₁₄-alkyl-benzylammonium chloride, tetrabutylammonium hydroxide,18-crown-6, triethylbenzylammonium chloride and trimethylbenzylammoniumchloride.

The reaction temperature can be varied within a substantial range incarrying out process (c) according to the invention. It is in generalbetween 0° C. and +120° C., preferably between +20° C. and +80° C.

For carrying out process (c) according to the invention, in general 1.0to 50 moles, preferably 1.0 to 20 moles, of halide of the formula (VI)and 0.01 to 1.0 mole of phase transfer catalyst are employed per mole ofstarting compound of the formula (I). The reaction is carried out andthe reaction products are worked up and isolated analogously to knownprocesses (see, for example, "Organikum", 15th edition, VEB DeutscherVerlag der Wissenschaften Berlin 1981, page 421 et seq.).

Processes (a), (b) and (c) according to the invention are in generalcarried out under normal pressure. However, it is also possible for themto be carried out under increased or reduced pressure.

Besides being used as herbicidal active compounds, the compounds of theformula (I) according to the invention can also be used as intermediateproducts for the synthesis of further active compounds. For example,they can be reacted with amines to give the corresponding5-amino-1-aryl-4-nitropyrazoles, which are likewise herbicidally activeand are the subject of a previous patent application which has beenfiled by the Applicant Company (see German Pat. No. 3,402,308 of24.01.1984).

The active compounds according to the invention can be used asdefoliants, desiccants, agents for destroying broad-leaved plants and,especially, as weed-killers. By weeds, in the broadest sense, there areto be understood all plants which grow in locations where they areundesired. Whether the substances according to the invention act astotal or selective herbicides depends essentially on the amount used.

The active compounds according to the invention can be used, forexample, in connection with the following plants:

Dicotyledon weeds of the genera:

Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga,Chenopodium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium,Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Carduus,Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica,Abutilon, Emex, Datura, Viola, Galeopsis, Papaver and Centaurea.

Dicotyledon cultures of the genera:

Gossypium, Glycine, Beta, Daucus, Phaseolus, Pisum, Solanum, Linum,Ipomoea, Vicia, Nicotiana, Lycopersicon, Arachis, Brassica, Lactuca,Cucumis and Cucurbita.

Monocotyledon weeds of the genera:

Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca,Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum,Agropyron, Cynodon, Monochoria, Fimbristylis, Sagittaria, Eleocharis,Scirpus, Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Agrostis,Alopecurus and Apera.

Monocotyledon cultures of the genera:

Oryza, Zea, Triticum, Hordeum, Avena, Secale, Sorghum, Panicum,Saccharum, Ananas, Asparagus and Allium.

However, the use of the active compounds according to the invention isin no way restricted to these genera, but also extends in the samemanner to other plants.

The compounds are suitable, depending on the concentration, for thetotal combating of weeds, for example on industrial terrain and railtracks, and on paths and squares with or without tree plantings.Equally, the compounds can be employed for combating weeds in perennialcultures, for example afforestations, decorative tree plantings,orchards, vineyards, citrus groves, nut orchards, banana plantations,coffee plantations, tea plantations, rubber plantations, oil palmplantations, cocoa plantations, soft fruit plantings and hopfields, andfor the selective combating of weeds in annual cultures.

Besides having a particularly good generally herbicidal activity, theactive compounds of the formula (I) according to the invention alsoexhibit a considerably improved selectivity towards crop plants inimportant crops and can be employed as agents for selectively combatingweeds in dicotyledon crops, such as, for example, sugar beet, cottonplantations, soya beans or groundnuts, and also in monocotyledon crops,in particular cereals, such as, for example, wheat.

The active compounds can be converted to the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, pastes, soluble powders, granules, suspension-emulsionconcentrates, natural and synthetic materials impregnated with activecompound, and very fine capsules in polymeric substances.

These formulations are produced in known manner, for example by mixingthe active compounds with extenders, that is liquid solvents and/orsolid carriers, optionally with the use of surface-active agents, thatis emulsifying agents and/or dispersing agents and/or foam-formingagents.

In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents. As liquid solvents,there are suitable in the main: aromatics, such as xylene, toluene oralkyl naphthalenes, chlorinated aromatics and chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic hydrocarbons, such as cyclohexane or paraffins, forexample petroleum fractions, mineral and vegetable oils, alcohols, suchas butanol or glycol as well as their ethers and esters, ketones, suchas acetone, methyl ethyl ketone, methyl isobutyl ketone orcyclohexanone, strongly polar solvents, such as dimethylformamide anddimethylsulfoxide, as well as water.

As solid carriers there are suitable: for example ammonium salts andground natural minerals, such as kaolins, clays, talc, chalk, quartz,attapulgite, montmorillonite or diatomaceous earth, and ground syntheticminerals, such as highly disperse silicic acid, alumina and silicates,as solid carriers for granules there are suitable: for example crushedand fractionated natural rocks such as calcite, marble, pumice,sepiolite and dolomite, as well as synthetic granules of inorganic andorganic meals, and granules of organic material such as sawdust, coconutshells, maize cobs and tobacco stalks; as emulsifying and/orfoam-forming agents there are suitable: for example non-ionic andanionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkylsulfonates, alkylsulfates, arylsulfonates as well asalbumin hydrolyzation products; as dispersing agents there are suitable:for example lignin-sulfite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, as well as naturalphospholipids, such as cephalins and lecithins, and syntheticphospholipids, can be used in the formulations. Further additives can bemineral and vegetable oils.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs and metal phthalocyaninedyestuffs, and trace nutrients such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95 percent by weightof active compound, preferably between 0.5 and 90%.

The active compounds according to the invention, as such or in the formof their formulations, can also be used, for combating weeds, asmixtures with known herbicides, finished formulations or tank mixesbeing possible.

Possible components for the mixtures are known herbicides, such as, forexample,1-amino-6-ethylthio-3-(2,2-dimethylpropyl)-1,3,5-triazine-2,4(1H,3H)-dioneor N-(2-benzothiazolyl)-N,N'-dimethyl-urea, for combating weeds incereals; 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one, forcombating weeds in sugar beet, and4-amin-6-(1,1-dimethylethyl)-3-methylthio-1,2,4-triazin-5(4H)-one, forcombating weeds in soya bean.

Mixtures with heteroaryl-oxyacetamides;N,N-dimethyl-N'-(3-chloro-4-methylphenyl)-urea,N,N-dimethyl-N'-(4-isopropylphenyl)-urea,4-amino-6-t-butyl-3-ethylthio-1,2,4-triazin-5(4H)-one,2,4-dichlorophenoxyacetic acid, 2,4-dichlorophenoxypropionic acid,(2-methyl-4-chlorophenoxy)-acetic acid,(4-chloro-2-methyl-phenoxy)-propionic acid, chloroacetic acidN-(methoxymethyl)-2,6-diethylanilide, 0-(methoxycarbonylaminophenyl)N-phenyl-carbamate; 2,6-dinitro-4-trifluoromethyl-N,N-dipropylaniline,2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate; butyl2-<4-[(5-trifluoromethyl-2-pyridinyl)-oxy]-phenoxy>-propanoate;S-(2,3,3-trichloroallyl)-N,N-diisopropyl-thiocarbamate;5-amino-4-chloro-2-phenyl-2,3-dihydro-3-oxo-pyridazine;methyl-6,6-dimethyl-2,4-dioxo-3-[1-(2-propenyloxyamino)butylidene)]-cyclohexanecarboxylicacid; 3,5-diiodo-4-hydroxybenzonitrile;3-isopropyl-2,1,3-benzothiadiazin-4-one 2,2-dioxide;2-chloro-N-[4-methoxy-6-methyl-1,3,5-triazin-2-yl)-aminocarbonyl]-benzenesulfonamide;4-ethylamino-2-t-butylamino-6-methylthio-s-triazine;N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitroaniline and2-<4-[(3-chloro-5-trifluoromethyl-2-pyridinyl)-oxy]-phenoxy>-propanoicacid and -propanoic acid ethyl ester are also possible. Surprisingly,some mixtures also show a synergistic action.

Mixtures with other known active compounds, such as fungicides,insecticides, acaricides, nematicides, bird repellants, plant nutrientsand agents which improve soil structure, are also possible.

The active compounds can be used as such, in the form of theirformulations or in the use forms prepared therefrom by further dilution,such as ready-to-use solutions, suspensions, emulsions, powders, pastesand granules. They are used in the customary manner, for example bywatering, spraying, atomising or scattering.

The active compounds according to the invention can be applied eitherbefore or after emergence of the plants.

They can also be incorporated into the soil before sowing.

The amount of active compound used can vary within a substantial range.It depends essentially on the nature of the desired effect. In general,the amounts used are between 0.01 and 15 kg of active compound perhectare of soil surfaces, preferably between 0.01 and 5 kg per ha.

The preparation and use of the active compounds according to theinvention can be seen from the following examples.

PREPARATION EXAMPLES Example 1 according to process (a) ##STR26##

26 ml (0.62 mole) of fuming nitric acid are added dropwise to asuspension of 7.0 g (0.025 mole) of5-chloro-1-(2,4,6-trichlorophenyl)-pyrazole in 30 ml of acetic anhydrideat room temperature in the course of 2.5 hours, with stirring, such thatthe internal temperature does not rise above 35° C. (about 10 ml/hour).When the addition has ended, the mixture is subsequently stirred at roomtemperature for 1 hour and poured onto ice-water, the oily product istaken up in chloroform, the mixture is washed in each case twice withsaturated sodium carbonate solution and water and dried over sodiumsulphate and the solvent is removed in vacuo. The crystalline residue isdigested with petroleum ether, filtered off with suction and dried.

6.0 g (73% of theory) of5-chloro-4-nitro-1-(2,4,6-trichlorophenyl)-pyrazole of melting point 78°C.-84° C. are obtained.

Example 2 according to process (b) ##STR27##

4.8 ml (0.04 mole) of t-butyl nitrite are added dropwise to 5.2 g (0.014mole) of5-amino-4-nitro-1-(2,3,6-trichloro-4-trifluoromethylphenyl)-pyrazole in16 ml (0.18 mole) of bromoform in the course of 10 minutes, withstirring, during which the temperature of the reaction mixture rises to50° C. When the addition has ended, the mixture is stirred at the refluxtemperature for a further hour and concentrated in vacuo and the oilwhich remains is purified by column chromatography (silica gel/eluant:chloroform/acetone 9:1).

5.0 g (82% of theory) of5-bromo-4-nitro-1-(2,3,6-trichloro-4-trifluoromethylphenyl)-pyrazole ofmelting point 97° C.-99° C. are obtained.

The 1-aryl-4-nitropyrazoles of the general formula (I) listed in thefollowing table are obtained in a corresponding manner and according tothe general preparation information:

                  TABLE 2                                                         ______________________________________                                         ##STR28##                     (I)                                                                                       Melting                            Example                                    point                              No.    Hal    R.sup.1 R.sup.2                                                                           R.sup.3                                                                              R.sup.4                                                                           R.sup.5                                                                             (°C.)                       ______________________________________                                        3      Cl     Cl      H   CF.sub.3                                                                             H   Cl    82-84                              4      Cl     Cl      H   OCF.sub.3                                                                            H   H     64-70                              5      Br     Cl      H   CF.sub.3                                                                             H   Cl    96                                 6      Br     Cl      H   CF.sub.3                                                                             H   Br    89-97                              7      Br     OCF.sub.3                                                                             H   Br     H   Br    86                                 8      Br     Cl      H   SO.sub.2 CF.sub.3                                                                    H   Cl    142-144                            9      Br     Cl      H   CF.sub.3                                                                             H   H     oil                                10     Br     Cl      Cl  SCF.sub.3                                                                            H   Cl    oil                                11     Br     Cl      H   OCF.sub.3                                                                            H   H     83                                 12     Br     Cl      Cl  OCF.sub.3                                                                            H   Cl    oil                                ______________________________________                                    

PREPARATION OF THE STARTING COMPOUNDS EXAMPLE II-1 ##STR29##

200 g (0.76 mole) of 1-(2,4,6-trichlorophenyl)-4H-Δ² -pyrazolin-5-oneare heated together with 500 ml (837.5 g=2.95 moles) of phosphorusoxychloride at 160° C. in an autoclave for 16 hours. For working up, thecooled reaction mixture is poured onto ice and stirred for 15 minutes,the precipitate is filtered off with suction and rinsed with water and,for purification, the residue is stirred in concentrated aqueous ammoniasolution at about 40° C. for 0.5 hour, filtered off with suction again,rinsed with water and dried. For further purification, the dry powder isdissolved in chloroform, the solution is washed with water, thechloroform phase is dried over sodium sulphate and the solvent isremoved in vacuo.

118 g (55% of theory) of 5-chloro-1-(2,4,6-trichlorophenyl)-pyrazole ofmelting point 96° C. are obtained.

The 1-aryl-5-halogenopyrazoles of the general formula (II) listed in thefollowing table are obtained in a corresponding manner and according tothe general preparation information: ##STR30##

                  TABLE 3                                                         ______________________________________                                        Example II-2                                                                                              Oil                                               Example II-3                                                                             ##STR31##        Melting point 70-72° C.                    Example III-1                                                                            ##STR32##                                                          ______________________________________                                    

7.5 g (0.0227 mole) of5-amino-1-(2,3,6-trichloro-4-trifluoromethylphenyl)-pyrazole (seeExample XIV-1) and 2.2 ml (2.3 g=0.023 mole) of acetic anhydride in 20ml of glacial acetic acid are stirred at room temperature for about 4hours until the starting substance can no longer be detected in thethin-layer chromatogram. A further 2.7 ml (2.9 g=0.0288 mole) of aceticanhydride and, at 5° C. to 10° C., 1.2 ml (1.8 g=0.028 mole) of 98percent strength nitric acid are then added, the mixture is stirred atroom temperature for 8 hours, the solvent is removed in vacuo and theresidue is taken up in 30 ml of ethanol and 20 ml of concentratedhydrochloric acid.

The mixture is heated at the reflux temperature for 12 hours andconcentrated in vacuo, the residue is taken up in 100 ml of methylenechloride, the mixture is washed carefully (evolution of CO₂) with 100 mlof saturated sodium bicarbonate solution and dried over magnesiumsulphate and the solvent is removed in vacuo.

7.5 g (84% of theory) of5-amino-4-nitro-1-(2,3,6-trichloro-4-trifluoromethylphenyl)-pyrazole ofmelting point 78° C. to 85° C. are obtained.

Example VIII-1 ##STR33##

200 g (0.704 mole) of 1,2,3,4-tetrachloro-5-trifluoromethylbenzene and240 ml (247.2 g/4.94 moles) of hydrazine hydrate in 500 ml of dioxaneare heated under reflux for 14 hours. The heavier (aqueous) phase isremoved from the cooled two-phase reaction mixture and the organic phaseis concentrated to dryness in vacuo. The residue is suspended in 600 mlof water and 100 ml of methylene chloride, the pH is brought to 10 with10 percent strength aqueous sodium hydroxide solution and the mixture iswarmed slowly to 30° C. to 35° C., two clear phases forming from thecloudy suspension. The mixture is allowed to cool to room temperature,the organic phase is separated off, washed with 200 ml of concentratedaqueous sodium chloride solution and dried over magnesium sulfate andthe solvent is removed in vacuo. The crude product is stirred in boilinghexane for 3 to 4 hours, the mixture is then cooled at 0° C. to 5° C.for 15 hours and the product is filtered off cold with suction and driedin vacuo at 50° C. for 2 to 3 hours.

146 g (71.2% of theory) of2,3,6-trichloro-4-trifluoromethyl-phenylhydrazine of melting point67°-70° C. with a content, determined by gas chromatography, of 96% areobtained.

The following compounds are obtained in a corresponding manner oraccording to the general preparation information:

Example VIII-2 ##STR34## Example VIII-3 ##STR35## Example VIIIa-1##STR36##

105 g (0.5 mole) of 2,4,6-trichlorophenylhydrazine and 108 g (0.5 mole)of diethyl ethoxymethylenemalonate are heated under reflux in 500 ml ofethanol for 5 hours, the mixture is then stirred at room temperature for12 hours and subsequently cooled to -10° C. and the residue is filteredoff and dried.

N-[2,2-Bis-(ethoxycarbonyl)-vinyl]-N'-(2,4,6-trichlorophenyl)-hydrazineof melting point 92° C. is obtained.

The following compounds are obtained in a corresponding manner:

Example VIIIa-2 ##STR37## Example VIIIa-3 ##STR38## Example IX-1##STR39##

35.8 g (0.094 mole) ofN-[2,2-bis(ethoxycarbonyl)-vinyl]-N'-(2,4,6-trichlorophenyl)-hydrazineare slowly heated to 170° C. and are stirred at 170° C. to 175° C. for45 minutes, during which 11 ml of ethanol are simultaneously distilledoff and the residue slowly solidifies.

The residue obtained is stirred with acetonitrile and filtered off withsuction.

26 g (82.4% of theory) of4-ethoxycarbonyl-5-hydroxy-1-(2,4,6-trichlorophenyl)-pyrazole of meltingpoint 228° C. are obtained.

The following compound is obtained in a corresponding manner:

Example IX-2 ##STR40## Example X-1 ##STR41##

3 g (0.075 mole) of sodium hydroxide--dissolved in 3 ml of water--areadded to 5 g (0.015 mole) of4-ethoxycarbonyl-5-hydroxy-1-(2,4,6-trichlorophenyl)-pyrazole in 75 mlof ethanol and the mixture is heated under reflux for 12 hours; themixture is allowed to cool, a further 3 g (0.075 mole) of sodiumhydroxide, dissolved in 3 ml of water, are added and the mixture isheated at the reflux temperature for another 12 hours. When the startingsubstance can no longer be detected in the thin-layer chromatogram, themixture is acidified with concentrated hydrochloric acid and heatedagain at the reflux temperature for 3 hours, the reaction mixtureobtained is filtered, the filtrate is concentrated, the residue is takenup in chloroform, the mixture is washed with water and dried over sodiumsulphate and the solvent is removed in vacuo.

1 g (25.3% of theory) of 1-(2,4,6-trichlorophenyl)-4H-Δ²-pyrazolin-5-one of melting point 202° C. is obtained.

(Alternative preparation possibility)

100 g (0.26 mole) ofN-[2,2-bis(ethoxycarbonyl)-vinyl]-N'-(2,4,6-trichlorophenyl)-hydrazineand 200 g-(5 moles) of sodium hydroxide are refluxed in 1,400 ml ofwater for 12 hours. The cooled reaction mixture is carefully acidifiedwith concentrated hydrochloric acid while stirring vigorously (evolutionof CO₂) and the solid which has precipitated is filtered off withsuction and dried in air. It can be recrystallised from ethanol.

53 g (77% of theory) of 1-(2,4,6-trichlorophenyl)-4H-Δ² -pyrazolin-5-oneof melting point 202° C. are obtained.

The following pyrazolinones of the formula (X) are obtained in acorresponding manner and according to the general preparationinformation: ##STR42##

Example X-2 ##STR43## Example X-3 ##STR44## Example XIV-1 ##STR45##

57 ml (62.7 g=0.71 mole) of 2-chloroacrylonitrile are added dropwise to45 g (0.17 mole) of 2,3,6-trichloro-4-trifluoromethyl-phenylhydrazineand 35 mg (0.1 mmol) of disodium ethylenediaminetetraacetate (TitriplexIII) in 260 ml of methanol at the reflux temperature in the course of 30minutes, and the mixture is stirred at the reflux temperature (about 65°C.) for a further 5 hours. The reaction mixture is concentrated invacuo, the residue is taken up in 260 ml of methanol, and 15.4 ml (0.541mole) of concentrated sulfuric acid are added dropwise at roomtemperature in the course of 15 minutes, with stirring. The temperatureof the reaction mixture thereby rises to 32° C. When the addition hasended, the mixture is stirred at 55° C. for 30 hours and cooled to roomtemperature, 56 g (0.534 mole) of sodium carbonate are added, themixture is stirred again at room temperature for 4 hours andconcentrated in vacuo, the residue is taken up in 550 ml of methylenechloride, 55 ml of water are added, the mixture is stirred at roomtemperature for 8 hours, the organic phase is separated off, washed with250 ml of concentrated aqueous sodium chloride solution and dried overmagnesium sulphate and the solvent is removed in vacuo.

52.6 g (94% of theory) of5-amino-1-(2,3,6-trichloro-4-trifluoromethyl-phenyl)-pyrazole of meltingpoint 109° C.-114° C. are obtained.

Preparation of secondary products Example (III-2) ##STR46##

2.8 g (0.0086 mole) of5-chloro-4-nitro-1-(2,4,6-trichlorophenyl)-pyrazole are heated at 160°C. in 100 ml of ammonia-saturated ethanol in a bomb tube or autoclavefor 10 hours. The cooled reaction mixture is concentrated, the residueis taken up in chloroform and the mixture is washed with water, driedover sodium sulfate and concentrated in vacuo. The crystalline residueis recrystallised from toluene.

2.2 g (85% of theory) of5-amino-4-nitro-1-(2,4,6-trichlorophenyl)-pyrazole of melting point 218°C.-220° C. are obtained.

Use Examples

The compound shown below was employed as the comparison substance in thefollowing use examples: ##STR47##4-Cyano-5-propionamido-1-(2,3,4-trichloro-phenyl)-pyrazole (known fromDE-OS (German Published Specification) No. 3,226,513).

Example A Pre-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Seeds of the test plants are sown in normal soil and, after 24 hours,watered with the preparation of the active compound. It is expedient tokeep constant the amount of water per unit area. The concentration ofthe active compound in the preparation is of no importance, only theamount of active compound applied per unit area being decisive. Afterthree weeks, the degree of damage to the plants is rated in % damage incomparison to the development of the untreated control. The figuresdenote:

0%=no action (like untreated control)

100%=total destruction

In this test, a clear superiority in selectivity towards useful plantsin comparison with the prior art is shown, for example, by the compoundaccording to the preparation example: (3)

Example B Post-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof active compound is mixed with the stated amount of solvent, thestated amount of emulsifier is added and the concentrate is diluted withwater to the desired concentration.

Test plants which have a height of 5-15 cm are sprayed with thepreparation of the active compound in such a way as to apply theparticular amounts of active compound desired per unit area. Theconcentration of the spray liquor is so chosen that the particularamounts of active compound desired are applied in 2,000 l of water/ha.After three weeks, the degree of damage to the plants is rated in %damage in comparison to the development of the untreated control. Thefigures denote:

0% =no action (like untreated control)

100% =total destruction

In this test, a clear superiority in selectivity towards useful plantsin comparison with the prior art is shown, for example, by the compoundaccording to the following preparation example: (3)

We claim:
 1. A 1-arylpyrazole of the formula ##STR48## in which Halrepresents halogen,R¹ and R³ independently of one another representcyano, nitro or halogen, or represent in each case straight-chain orbranched alkyl, alkoxy or alkoxycarbonyl with in each case 1 to 4 carbonatoms, or represent in each case straight-chain or branchedhalogenoalkly with in each case 1 to 4 carbon atoms and 1 to 9 identicalor different halogen atoms, or represent a radical --S(O)_(n) --R⁶ andR², R⁴ and R⁵ independently of one another and independently of R¹ andR³ represent the same radical as R¹ and R³ represent the same radical asR¹ and R³ and also represent hydrogen,and wherein R⁶ represent amino, orin each case straight-chain or branched alkyl, alkylamino, dialkylaminoor halogenoalkyl with in each case 1 to 4 carbon atoms in the individualalkyl parts and, in the case of halogenoalkyl, with 1 to 9 identical ordifferent halogen atoms and n represents the number 0, 1 or
 2. 2. A1-arylpyrazole according to claim 1 in whichHal represents fluorine,chlorine, bromine or iodine, R¹ and R³ independently of one anotherrepresent cyano, nitro, fluorine, chlorine, bromine, iodine, methyl,ethyl, n- or i-propyl or n-, i-, s- or t-butyl, or represent methoxy,ethoxy, methoxycarbonyl or ethoxycarbonyl, or represent trifluoromethyl,trichloromethyl, dichlorofluoromethyl, difluorochloromethyl,chloromethyl, dichloromethyl, difluoromethyl, pentafluoroethyl,tetrafluoroethyl, trifluorochloroethyl, trifluoroethyl,difluorodichloroethyl, trifluorodichloroethyl or pentachloroethyl, orrepresent trifluoromethoxy, trichloromethoxy, dichlorofluoroethoxy,difluorochloromethoxy, chloromethoxy, dichloromethoxy, difluoromethoxy,pentafluoroethoxy, tetrafluoroethoxy, trifluorochloroethoxy,trifluoroethoxy, difluorodichloroethoxy, trifluorodichloroethoxy orpentachloroethoxy, or represent a radical --S(O)_(n) --R⁶ and R², R⁴ andR⁵ independently of one another and independently of R¹ and R³ representthe same radicals as R¹ and R³, and also represent hydrogen,and whereinR⁶ represents amino, methylamino, ethylamino, dimethylamino,diethylamino, fluorodichloromethyl, difluoromethyl, tetrafluoroethyl,trichloroethyl, trifluoromethyl, methyl or ethyl and n represent thenumber 0, 1 or 2.